1. Field of the Invention
The present invention relates to an engine valve timing control apparatus that controls the open timing of an intake valve of an engine.
2. Background Information
Japanese Laid-Open Patent Publication No. 2002-349301 discloses an example of known mechanisms for changing the open/close timing of an intake valve of an engine in order to achieve both good torque performance in low to medium vehicle speed regions and good output power in high vehicle speed regions. If the valve open/close timing is changed too abruptly, then it is possible that the engine will stall. The above mentioned reference addresses this issue by limiting the valve timing change rate at which the valve open/close timing is changed based on the engine speed and the direction in which the open/close timing is being changed (i.e., advanced or retarded).
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved engine intake valve timing control apparatus. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.